Previously known burners and burner controls for stoves employed in cooking appliances often incorporate a dual proportional gas valve for controlling the amount of gas delivered to the burner that generates a flame in response to a spark delivered to an ignitor at the burner. Most often, rotation of a knob proportionally controls the opening and the closing of the valve to control the amount of gas delivered to the burner and thus the size of the flame delivering heat to the cooking vessel. Moreover, a predetermined rotation of the knob also controls delivery of a charge to the ignitor. Nevertheless, these simple burner controls maintain a constant flame even during a simmering cooking step and thus provoke hot spots in the receptacles placed on the burner. Moreover, to assure a low flame when a low heat transfer is desired, the cooking tops have been constructed to include small burners so that a low BTU output may be maintained. However, such low but constant flame output typically results in uneven heat distribution throughout the cooking receptacle resulting in hot spots. Moreover, the low BTU output of a very small flame can also create problems with previously known flame sensing circuitry of a spark rectification system often used in gas appliances to assure that gas delivered to the burner is combusted.
Another previously known cooking top employing a burner control to address the above problems comprises a system for pulsing the flame so that the flame is on or off for selected period of time within a cycle. However, the previously known controls for such burners have been complicated to operate in that multiple controls are used to control gas flow and the operation of the ignitor at the burner. In particular, Scholtes of Thionville, France and Rosiere marketed burner controls employing an electronic sequencer from R. V. Construction electriques of Balvozy, France in which one actuator was used to periodically control ignitor timing periods while another actuator controls the volume of gas passed through the valve. Accordingly, the cook was required to maintain control over two actuators simultaneously in order to properly operate the stove at a desired cooking condition.
Another previously known burner control provides an actuator that presets a desired temperature for a cooking vessel. An electronic circuit controls the flame on and flame off time to maintain a set temperature in response to a sensor which touches the bottom of the cooking vessel. The amount of gas flow to maintain this temperature setting is modulated by a temperature responsive, gas flow control valve. However, the temperature sensor is subjected to continuously changing heating and cooling cycles and can substantially affect the durability of many of the components subjected to cycling in the cooking apparatus.